Data and code associated with "Seasonal differences in predation risk among seagrass epifauna species stabilize community-level predation over time"

Predation risk varies through space and time due to changing refuge
quality, predator communities, and prey traits. Despite this, ecological
research is often focused on measuring average predation risk at the
community level. While this can give important information about overall
trophic transfer and ecological efficiency, it ignores differences in
predation risk among prey species within a community, which may be
important determinants of species coexistence and local diversity. We used
crustaceans associated with temperate seagrass in Northern California to
explore the relationship between seasonal variation in among-species and
community-level predation risk for a community of morphologically distinct
prey. We measured predation risk of the four most abundant and widespread
prey species at six field sites every two to six weeks for one year. At
the community level, sites differed significantly in their annual
variation in predation risk, and these differences were correlated with
the amount of variation in the among-species predation risk. When there
was more within-year variation in predation risk among the four prey
species, predation risk at the community level was more stable across the
year. On the other hand, when each prey species in the community had
similar levels of predation risk throughout the year, predation as a
community-level process was much more seasonal and variable. Variation in
predation risk also changed across a gradient of seagrass cover, a proxy
for refuge quality. Sites with greater seagrass cover had less annual
variation in community-level predation risk and more variation in
predation risk among the four species at any given time point. In
contrast, at sites with less eelgrass, all species were consumed at the
same rate throughout the year, suggesting previously demonstrated
differences in antipredator strategies among species are less relevant in
the absence of habitat-forming species. We suggest that larger
species-specific differences in predation risk throughout a year result in
a more stable level of predation risk for the whole community, and that
this may be driven by increased refuge provided by seagrass habitat
mediating different prey species’ relative levels of susceptibility to
predation.